Molecular surveillance of penicillinase-producing Neisseria gonorrhoeae to inform empiric treatment in remote settings: experience over 12 years

OBJECTIVES: The remote regions of Western Australia (WA) have high gonorrhoea notification rates but low Neisseria gonorrhoeae penicillin resistance permitting the use of empiric combination oral amoxicillin, azithromycin and probenecid therapy. The predominance of molecular-based gonorrhoea diagnoses and consequent reduced phenotypic susceptibility data required PCR-based N. gonorrhoeae penicillin resistance surveillance to ensure the ongoing reliability of oral penicillin-based therapy for uncomplicated gonorrhoea in this setting. MATERIALS AND METHODS: N. gonorrhoeae PCR-positive genital and non-genital specimens were systematically assessed across remote regions of WA for penicillinase production from 2012 to 2025 by detection of the N. gonorrhoeae TEM-1 plasmid using a specific real-time PCR. RESULTS: In 2012 <5% of N. gonorrhoeae positive samples in all remote regions were penicillinase-producing. By 2024, penicillinase detection rates had increased to >5% across three of the four remote regions prompting a review of the penicillin-based oral therapy in these regions. CONCLUSIONS: The continued recommendation of oral penicillin-based therapy for locally acquired uncomplicated gonorrhoea in a highly endemic setting must be evidence-based to ensure its reliability. Molecular penicillin resistance surveillance was successfully used for this purpose in the remote regions of WA where most gonorrhoea diagnoses are by molecular tests.